- "If I have to burn half of the Eye of Terror and raze the Planet of the Sorcerers to find the means, I will break your Rubric, and let our Legion die at last."
- — Amon confronting Ahriman for the last time
The Brotherhood of Dust was a powerful Chaos Space Marine warband that consisted primarily of powerful exiled Thousand Sons Chaos Sorcerers founded by Amon, the former Captain of the 9th Fellowship of the Thousand Sons Legion, and the Equerry of Primarch Magnus the Red. He eventually confronted his former friend and later bitter rival, Ahzek Ahriman, in an epic sorcerous duel, but was ultimately defeated. Ahriman then absorbed the fallen sorcerer's power and took Amon's battle-plate, and assumed the mantle of leadership over the Brotherhood of Dust as his own. It is not known if the Brotherhood of Dust survived into the late 41st Millennium, or if they are one and the same with the Prodigal Sons, the warband of Chaos Space Marines that Ahriman currently leads.
Amon once served as a tutor to the Primarch Magnus the Red, before the arrival of the Thousand Sons Space Marine Legion on the world of Prospero during the Great Crusade in the late 30th Millennium. He eventually went on to become one of the XVth Legion's first Prosperine Astartes at the direct invitation of Magnus. Amon rose through the ranks to become the Captain of the 9th Fellowship. As a potent psyker, he became the founder of the XVth Legion's Corvidae Cult and its first Magister Templi. He also served as Equerry to Magnus, responsible for the Primarch's security and for officiating certain sorcerous rituals, amongst other duties. Amon would not only survive the battles of the Great Crusade, but the Razing of Prospero by the Space Wolves Legion during the early years of the Horus Heresy as well. At the height of this conflict, the mortally wounded Magnus opened a gateway through the Warp into the Eye of Terror where the Daemon World Sortiarius, better known as the Planet of the Sorcerers, had been prepared for Magnus and the remnants of his Legion by their new patron god, Tzeentch. Magnus was subsequently "rewarded" by Tzeentch by being transformed into a Daemon Prince.
Following their exile into the Eye of Terror, First Captain Ahzek Ahriman became hateful and contemptible of their gene-sire. When the "flesh-change" once again ran rampant amongst the survivors of the Thousand Sons and Magnus seemed to accept it, Ahriman set out to find a cure for the rapid mutation himself. In his own hatred and hubris, and utterly unaware of the ludicrousness of attempting to use the very energy of change to stop change, Ahriman delved into the sorcerous knowledge held in the Book of Magnus. Distilling the colossal collections of formulae, incantations and rites, and infusing the results with his own hatred of Magnus and angst at the fate of his Legion, Ahriman devised the canvas of a mighty arcane spell that would ultimately undo all the woe that had befallen his Battle-Brothers and thus protect them from the flesh-change for all eternity. Preliminary testing of the spell he called the Rubric generated great promise,but he quickly discovered that he lacked the raw power required to achieve permanent results. He then set to work gathering those amongst the remaining officers of the Thousand Sons who, like him, were disgusted by what had befallen their Legion and their Primarch. Gathering in a fell circle around Ahriman, this cabal of Sorcerers lent their power to Ahriman, who then unleashed the full power of his desperate spell.
Amon was amongst those who had joined Ahriman's breakaway cabal, those who had always been the most headstrong and possessed of the most psychic power in the XVth Legion. Those that had remained faithful to the Primarch were the second-rate, the ones who had not dared to join the casting of the Rubric. The counter-sorcery affected them all, preserving less than a hundred of the Legion's Sorcerers and condemning the rest, the Rubricae, to dust as their physical bodies were transformed into spectral energy. In the aftermath of the cataclysm, it became clear that the Rubric had either succeeded beyond all possible expectations or failed abominably, depending on how one looked at it. Ahriman himself, along with most of his cabal, were horrified by the result. Their brethren were now as they had intended, protected from the "flesh-change," though they paid for this protection with the destruction of their physical bodies. Instead of being struck down for their temerity by their enraged Primarch, Ahriman and the rest of his cabal were instead banished from the Planet of the Sorcerers.
As Ahriman was exiled, so too was his cabal, but Amon was determined to find all the secrets of the Rubric and perhaps restore some of his mindless, undead brothers back to life. Over the next one thousand standard years, as he continued to amass more power, Amon founded his own powerful warband known as the Brotherhood of Dust which consisted of many exiled Thousand Sons. He also gathered voidships, other Chaos Space Marines, hundreds of Rubricae and a number of apprentices, who themselves became formidable Chaos Sorcerers in their own right. It was Amon's intent to see the suffering of his Legion ended, for he would undo the fell magic of the Rubric that had doomed his former Battle-Brothers to their unlife, so that he could release their tortured souls. Yet, despite all his grand schemes and designs, he still needed the wayward Ahriman, for only he possessed the necessary knowledge of the Rubric.
Amon sent out emissaries across the galaxy to chase rumors, no matter how minor, of the possible whereabouts of the former Thousand Sons Chief Librarian. During his quest, Amon came across other former members of the Thousand Sons. He sent his emissaries to his former brothers in the hopes of enticing them to join his warband. If they accepted, they would become a part of the Brotherhood of Dust, however, those that refused faced the prospect of annihilation -- both themselves and those that followed them. Eventually, Ahriman was discovered and captured by the Brotherhood of Dust. In an epic confrontation, the enraged Amon unleashed a powerful psychic attack against his former brother. During the ensuing duel, Ahriman revealed the final secret of the Rubric to his former brother -- it was a part of all Thousand Sons, bound into their very beings -- the Rubric ran through them all, linking them, sustaining them. Its power was in Ahriman's hands. Unable to pull his mind away from Ahriman, the Chaos Sorcerer caused Amon to spontaneously combust from the powerful psychic energy unleashed from the arcane spell. Amon's armour came apart, each component pulling away from the other, spilling grey dust into the turning wind.
The vortex of Warp power enveloped Ahriman and lifted him into the air, the separate pieces of Amon's armour aligning itself over his unarmoured, splayed body. Then, one plate at a time, they slid into place over Ahriman's flesh. Finally Amon's horned helm slipped over Ahriman's skull. The minds of the living Sorcerers of the Brotherhood of Dust teetered on the edge of indecision. The undead Rubricae simply waited. Raising his hands, Ahriman summoned Warpflames from the floor, which scoured the red lacquer from the armour of every Rubricae and Sorcerer. Then the flames flickered blue, and the silver armour became polished sapphire. Ahriman looked across the ranks of blue armoured warriors. Slowly, he knelt and bowed his head. He assumed the mantle of leadership of the Brotherhood of Dust, including its massive fleet and army of followers. It is not known in Imperial records if the Brotherhood of Dust is the same warband, now known as the Prodigal Sons, that Ahriman currently leads in the late 41st Millennium.
Notable Brotherhood of Dust Members
- Amon (Deceased) - Chaos Sorcerer Lord and warband founder and leader.
- Tolbek (Deceased) - Chaos Sorcerer and exiled member of Ahriman's cabal.
- Siamak (Deceased) - Chaos Sorcerer and exiled member of Ahriman's cabal.
- Zabaia (Deceased) - Chaos Sorcerer and exiled member of Ahriman's cabal.
- Helio Isidorus - Rubric Marine, former Thousand Sons Legionary.
- Mabius Ro - Rubric Marine, former Thousand Sons Legionary.
The Brotherhood of Dust wore Power Armour in the pre-Horus Heresy Legion colours of the Thousand Sons, favouring lacquered red with silver trim as well as ornate crests on their helmets similar to the striped cloth crowns once worn by ancient Gyptian pharaohs of Terra. Following Ahriman's takeover of the Brotherhood of Dust, their colours were replaced with polished sapphire blue and gold trim, akin to the post-Heresy colours of the Thousand Sons.
The Brotherhood of Dust, like the Thousand Sons of old, incorporates the XVth Legion's old iconography as their badge.
- Ahriman: Exile (Novel) by John French